CVE-2021-29651: Infoleak
Impact Using programmatic access on protected sites, one can get a signed login URL with pomeriumredirecturi set to an arbitrary URL. Then, if the user has already logged into Pomerium, they will be redirected to the specified pomeriumredirecturi with a JWT attached. This allows an outside attacker to get a signed login URL that, upon visiting it, will redirect a victim to the attacker’s site. This creates an issue of Open Redirect and, more seriously, JWT leakage.
With a leaked JWT, the attacker will be able to unveil the victim’s identity (.e.g. email address) by supplying the JWT to the authenticate service or verify.pomerium.com. In addition, if an application integrating Pomerium only verifies the iss claim and others but not the aud claim, the attacker will be able to access it as the victim.
Specific Go Packages Affected github.com/pomerium/pomerium/proxy
Patches Patched in Pomerium v0.13.4
For more information If you have any questions or comments about this advisory Open an issue in pomerium Email us at security@pomerium.com
Other sources
Pomerium before 0.13.4 has an Open Redirect (issue 1 of 2).
Affected Software
Event History
Frequently Asked Questions
What is CVE-2021-29651?
CVE-2021-29651 is a vulnerability that allows an attacker with programmatic access to obtain a signed login URL with a redirect to an arbitrary URL in Pomerium.
How does CVE-2021-29651 impact protected sites?
CVE-2021-29651 allows an attacker to redirect users who have already logged into Pomerium to a specified URL with a JWT attached.
What is the severity of CVE-2021-29651?
CVE-2021-29651 has a severity rating of medium (6.3).
Which versions of Pomerium are affected by CVE-2021-29651?
Pomerium versions up to exclusive version 0.13.4 are affected by CVE-2021-29651.
How can I fix CVE-2021-29651?
To fix CVE-2021-29651, update your Pomerium installation to version 0.13.4 or later.